Release from proactive interference in early Alzheimer's disease.

The study analyses the performance of 22 mild Alzheimer's disease (AD) patients on the Release from Proactive Interference (RPI) paradigm with the aim to investigate the relationship of RPI with frontal function. Twenty-one normal elderly subjects, age and education matched, constituted the control group. Patients with AD were found to recall less words on each trial of the RPI than did the controls. The analysis of Proactive Interference (PI) and Release from PI, in AD patients, by using Anova (trial x group), showed a significant effect of trial and group but not a group by trial interaction. These results indicate a similarity between the performance of AD patients and normal controls on the Release from Proactive Interference paradigm. Despite the similar pattern of performance, AD patients were significantly inferior to normal controls with regard to global performance level. The AD patients' scores on "frontal lobe" tests were correlated with an index of RPI (shift condition index). The only significant result was with the number of categories on the Wisconsin Card Sorting Test, suggesting a weak correlation between RPI and "frontal lobe" function.